Bottom Line:
Albino animals are rare in the wild; this trait is associated with easy detection by predators, non-native or damaged environments, and exclusively aphotic environments in total darkness.Albinism-related ostracism results in a solitary existence, usually followed by enhanced predation risk.The motivation for an individual's exclusion from a group appears to be the avoidance of the predation risk that increases not only for an odd individual but also for conspecifics within a group.

ABSTRACTPhysiological and behavioural constraints hinder albino individuals. Albino animals are rare in the wild; this trait is associated with easy detection by predators, non-native or damaged environments, and exclusively aphotic environments in total darkness. The social aspect of albinism is reported only for human beings, and the effect is distinguishable in time and space when social benefits, are used to a limited the extent. Thus far, the social consequences of albinism for animals remain unknown. We used socially established groups of the pigmented catfish, (Silurus glanis), to observe space and temporal distance detachment of albino specimens in laboratory conditions. The albino fish were separated at larger distances from the group than pigmented individuals with the same social status determined by familiarity, and this asymmetry also varied in time. Albinism-related ostracism results in a solitary existence, usually followed by enhanced predation risk. The motivation for an individual's exclusion from a group appears to be the avoidance of the predation risk that increases not only for an odd individual but also for conspecifics within a group. Our findings indicate a role for albinism in behavioural processes related to sociality in a group of conspecifics.

pone.0128279.g001: Illustrative figure of the experimental design and the artificial stream.

Mentions:
The laboratory experiment was conducted between November 15 and December 17, 2010, in an oval artificial stream (see [18] for details). For the purpose of this experiment, only the straight part of the stream was used (beige colour, 3.75 m long, 0.49 m wide and 0.32 m deep). This segment was divided into 5 subunits using 7 equidistant PIT antennae (Fig 1), and mesh was placed over the outer antennae to prevent the fish from escaping from the observed stream segment. The antennae (inner area 0.49 m × 0.25 m) were designed to serve as frames for the detection of fish swimming through them and were connected to a recorder that stored the detection information (PIT tag code, date, time and antenna number) in its internal memory. The handling conditions were comparable to those in the holding tanks, and the water quality and flow were controlled by 2 Pressure-Flo 5000 units (60 L/min each). This arrangement generated a visible current (0.01 m s−1) circulating through the stream; however, the fish did not have to swim continuously to maintain their positions.

pone.0128279.g001: Illustrative figure of the experimental design and the artificial stream.

Mentions:
The laboratory experiment was conducted between November 15 and December 17, 2010, in an oval artificial stream (see [18] for details). For the purpose of this experiment, only the straight part of the stream was used (beige colour, 3.75 m long, 0.49 m wide and 0.32 m deep). This segment was divided into 5 subunits using 7 equidistant PIT antennae (Fig 1), and mesh was placed over the outer antennae to prevent the fish from escaping from the observed stream segment. The antennae (inner area 0.49 m × 0.25 m) were designed to serve as frames for the detection of fish swimming through them and were connected to a recorder that stored the detection information (PIT tag code, date, time and antenna number) in its internal memory. The handling conditions were comparable to those in the holding tanks, and the water quality and flow were controlled by 2 Pressure-Flo 5000 units (60 L/min each). This arrangement generated a visible current (0.01 m s−1) circulating through the stream; however, the fish did not have to swim continuously to maintain their positions.

Bottom Line:
Albino animals are rare in the wild; this trait is associated with easy detection by predators, non-native or damaged environments, and exclusively aphotic environments in total darkness.Albinism-related ostracism results in a solitary existence, usually followed by enhanced predation risk.The motivation for an individual's exclusion from a group appears to be the avoidance of the predation risk that increases not only for an odd individual but also for conspecifics within a group.

ABSTRACTPhysiological and behavioural constraints hinder albino individuals. Albino animals are rare in the wild; this trait is associated with easy detection by predators, non-native or damaged environments, and exclusively aphotic environments in total darkness. The social aspect of albinism is reported only for human beings, and the effect is distinguishable in time and space when social benefits, are used to a limited the extent. Thus far, the social consequences of albinism for animals remain unknown. We used socially established groups of the pigmented catfish, (Silurus glanis), to observe space and temporal distance detachment of albino specimens in laboratory conditions. The albino fish were separated at larger distances from the group than pigmented individuals with the same social status determined by familiarity, and this asymmetry also varied in time. Albinism-related ostracism results in a solitary existence, usually followed by enhanced predation risk. The motivation for an individual's exclusion from a group appears to be the avoidance of the predation risk that increases not only for an odd individual but also for conspecifics within a group. Our findings indicate a role for albinism in behavioural processes related to sociality in a group of conspecifics.